I'm certainly no expert, but we perceive depth because of the binocular vision effect when the eyes are in the front. You can see this by looking at an object at a distance and closing one eye. Notice the difference in the perception when one eye is closed. Because the eyes of a hog are more to the side, that would limit the frontal vision, and, it seems to me, limit depth perception.

All animals have strong/weak senses. Pigs sense of smell is among the best in the animal kingdom - eyesight among the worst. I can't speak specifically to depth perception, but I would imagine it's not very good.

The way pigs are built they are essentially looking at the ground most of the time. It is difficult for them to look up. They are probably myopic. As far as their sense of smell goes, I'm sure they can smell more acutely than people (notice I didn't say "better") but our dogs have better sense of smell than the pigs. That is very easy to see when you toss treats into the pasture. The smells will wake up the dogs whereas the pigs seem to have trouble finding stuff that is only a few feet away

Thanks all. I was just thinking that if they are depth perception challenged, then one could design loading/handling facilities to avoid having them step up to get into trailer or breeding pen. Might save time and frustration often spoke of with loading "Adventures", LOL.